Articles
COOLING BY NIGHT SKY RADIATION
Article number
148_16
Pages
135 – 142
Language
Abstract
Theoretical equations were derived which predict the cooling performance of night sky radiators.
Observations using four different radiators generally confirmed the theory and demonstrated that temperature depressions of 11 to 6C below air temperature with vapor pressures from 0.5 to 2 kPa can be achieved from black paint radiators with polyethylene covers.
Calculations of nightly cooling losses from various radiators in Phoenix, Arizona, showed that the required radiator surface areas are generally too large to be practical for cooling greenhouses, but offer some possibility for residential applications.
The theory presented can be used to predict the feasibility of night sky radiator use for other applications, climates, and radiator properties.
Observations using four different radiators generally confirmed the theory and demonstrated that temperature depressions of 11 to 6C below air temperature with vapor pressures from 0.5 to 2 kPa can be achieved from black paint radiators with polyethylene covers.
Calculations of nightly cooling losses from various radiators in Phoenix, Arizona, showed that the required radiator surface areas are generally too large to be practical for cooling greenhouses, but offer some possibility for residential applications.
The theory presented can be used to predict the feasibility of night sky radiator use for other applications, climates, and radiator properties.
Authors
B.A. Kimball
Keywords
Online Articles (120)